How to Evaluate the Effects of a TPN Administration

Total parenteral nutrition (TPN) is a very specialized form of nutrition administered intravenously through a subclavian catheter or another central venous catheter. It is used to provide the necessary nutrients to sustain life and support healing when a patient is incapable of digesting food through his digestive system because of major trauma, bowel paralysis, certain malignancies or other conditions that are expected to prevent feedings by mouth or into the gastrointestinal system for a minimum of 7 days. Evaluation of the long-term effects of TPN would be weight maintenance or weight gain unassociated with excess systemic fluids. Evaluating the effects of a single TPN administration involves assessing the therapy's potential side effects.

Things You'll Need

• Built-in bed scale or Hoyer lift weight scale
• Blood glucose monitor
• Blood glucose test strips
• Luer-lock syringes to draw blood from central catheter

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Instructions

• 1

  Weigh the patient before the first TPN administration, using a built-in bed scale or Hoyer lift weight scale. Continue to weigh the patient daily at approximately the same time of day. Daily weights are more reflective of liver, kidney or cardiovascular issues in the form of water retention than a weight gain secondary to caloric intake.

• 2

  Measure and document the patient's blood glucose level before hanging the first TPN bag, using blood glucose test strips. Take subsequent blood glucose measurements according to your facility's TPN protocol and on an as-needed (PRN) basis. Blood sugar levels are monitored to assess the effect of the TPN carbohydrate load on the patient's system.

• 3

  Schedule and obtain blood samples, using Luer-lock syringes to draw blood from the central venous catheter, for the following laboratory tests before hanging the first TPN bag: complete blood count (CBC), chromium level, comprehensive metabolic panel, copper level, magnesium level, manganese level, phosphorus level, prealbumin, selenium level, triglyceride levels and zinc levels. Take subsequent laboratory tests according to your facility's TPN protocol and on a PRN basis. Liver tests as part of the metabolic level help to assess the patient's response to the carbohydrate and fat load of the TPN administration. Monitoring triglycerides also helps to assess the patient's tolerance to the lipid component of the TPN feeding.

• 4

  Begin a 24-hour urine collection test to determine urea levels at the time you hang the first TPN bag or according to your facility's TPN protocol. Monitoring urea helps to assess the patient's tolerance with the protein component of the TPN feeding.

• 5

  Measure vital signs before you hang the first TPN bag. Continue to monitor vitals signs according to your facility's protocol or on a PRN basis. Changes in vital signs may indicate systemic infection, overfeeding, fluid overload and other serious side effects.